39-3
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter39 Configuring IPv6 Unicast Routing
Understanding IPv6
IPv6 Address Output Display
Simplified IPv6 Packet Header
Supported IPv6 Unicast Routing Features
These sections describe the IPv6 protocol features supported by the switch:
128-Bit Wide Unicast Addresses, page39-3
DNS for IPv6, page 39-4
Path MTU Discovery for IPv6 Unicast, page39-4
ICMPv6, page 39-4
Neighbor Discovery, page39-4
Default Router Preference, page39-5
IPv6 Stateless Autoconfiguration and Duplicate Address Detection, page 39-5
IPv6 Applications, page39-5
Dual IPv4 and IPv6 Protocol Stacks, page39-5
DHCP for IPv6 Address Assignment, page39-6
Static Routes for IPv6, page39-6
RIP for IPv6, page 39-7
OSPF for IPv6, page 39-7 (only on switches running the IP services image)
EIGRP for IPv6, page 39-7 (only on switches running the IP services image)
HSRP for IPv6, page 39-7 (only on switches running the IP services image)
SNMP and Syslog Over IPv6, page 39-7
HTTP(S) Over IPv6, page 39-8
Support on the switch includes expanded address capability, header format simplification, improved
support of extensions and options, and hardware parsing of the extension header. The switch supports
hop-by-hop extension header packets, which are routed or bridged in software.
The switch provides IPv6 routing capability over native Ethernet Inter-Switch Link (ISL) or 802.1Q
trunk ports for static routes, Routing Information Protocol (RIP) for IPv6, and Open Shortest Path First
(OSPF) Version 3 Protocol. It supports up to 16 equal-cost routes and can simultaneously forward IPv4
and IPv6 frames at line rate.

128-Bit Wide Unicast Addresses

The switch supports aggregatable global unicast addresses and link-local unicast addresses. It does not
support site-local unicast addresses.
Aggregatable global unicast addresses are IPv6 addresses from the aggregatable global unicast
prefix. The address structure enables strict aggregation of routing prefixes and limits the number of
routing table entries in the global routing table. These addresses are used on links that are aggregated
through organizations and eventually to the Internet service provider.